SpaceX’s Next Launch Will Carry NASA Solar Sail Experiment

When Falcon 1 takes off in a few weeks, one of the “piggyback” payloads will be a 4 kg (less than 10 lbs) NASA satellite about the size of a bread box that can unfurl into a 10 meter square solar sail on orbit. Click here for video.

Why is this exciting? Because unlike a lake, the vacuum of space has little to no drag, that means that the ‘wind’ that is pushing your sail can keep accelerating you and accelerating you till you are going much faster then a conventional rocket. What is actually pushing you are the photons from the sun hitting the sail. They exert a very slight force, but enough to consistently keep accelerating the spacecraft.

Even better is that means you fly through space without having to carry a lot of heavy rocket fuel on board. This makes it perfect for people who want to travel out really far- like past Pluto. (It is not as useful for short trips to the Moon, which would takes months with a solar sail versus three days with conventional rockets.)

The team at NASA is composed of the small satellite team at the NASA Ames Research Center in Mountain View, California and the alternative propulsion group at Marshall Space Flight Center in Huntsville, Alabama. They have joined forces to launch a highly exciting and innovative mission in short order (less than six months). If it is successful, it will be the first time a solar sailing spacecraft has been deployed in space.

The Planetary Society launched the very exciting Cosmos 1 solar sail mission back in 2005, but the rocket being used to deliver the spacecraft to orbit did not complete its scheduled first stage burn and
Cosmos 1 never got the chance to test out its solar sailing technology. Japan launched a thin film suborbitally in 2004, Russia has launched some solar reflectors (but not with the intention of using them for sailing), and Mariner IV used solar sail ‘paddles’ to help with attitude control back in 1964.

Falcon 1 was scheduled to launch from Kwajalein on June 24th but was bumped due to Army support equipment and tracking station scheduling conflicts. The new launch window for the long awaited third launch attempt of the Falcon 1 will be open July 29- August 6, 2008.

This payload means that if Falcon 1 successfully delivers its payload to low Earth orbit this time, we will have something cool to watch on the other end of the mission as well.

The best example I read of the power of solar sails versus conventional propulsion is that it took the Voyager probes 30 years to get to the edge of the solar system where they are still hurtling outward further every day. Although slower to get started, a solar sail could catch up with a Voyager spacecraft in a single decade.